1. Field of the Invention
Various types of petroleum-derived hydrocarbon oils undergo deterioration on storage, and particularly on exposure to air on standing for extended lengths of time. Thus fuel oils, such as diesel fuel, jet fuel, burner oil, and furnace oils undergo deterioration as evidenced by such changes as the formation of sediment. This deterioration depends in part on the composition of the blending stock which make up the fuel. In general the more cracked stocks used in making up the fuel blend, the greater the instability of the fuel. Similarly, fuel derived from star sands, shale oil, or by the H-Oil process generally have a higher naphthenic content and are less stable. Other factors contributing to instability would include the cleanliness of the fuel itself and the conditions of storage.
Sediment formation is undesirable for various reasons. The settling of the accumulated particles in tanks storing hydrocarbon oils requires periodic draining and cleaning of the storage tanks leading to temporary unavailability of storage capacity, substantial diversion of manpower, and waste disposal problems. Sediment formation in burner oil tends to plug strainers, burner tips, and injectors. In diesel fuel, such sediment tends to form sludge and varnish in the engine. If the oil is used as a heat exchange medium, as for example with jet fuel, the sediment tends to plug exchanger coils. It is apparent, therefore, that reduced sediment formation in hydrocarbon oils is very important.
One method of effecting sediment reduction would be to eliminate to a substantial degree, those processes leading to particulate formation, such as oxidation. Another method would be to prevent agglomeration and/or settling of the formed particulate matter by effectively maintaining the fine particles in a well dispersed state, so that the difficulties associated with the sediment formation either do not occur or are of substantially lessened severity.
It is the primary object of this invention to improve the stability of middle distillate fuels against the formation of precipitation of sediment.
2. Description of the Prior Art
U.S. Pat. No. 3,309,182 issued Mar. 14, 1967, discloses a polyether diamine as a stabilizer for petroleum distillate fuels.
U.S. Pat. No. 3,236,895 issued Feb. 22, 1966, discloses novel polyoxyalkylene polyamines and method of preparing these amines.
U.S. Pat. No. 3,654,370 issued Apr. 4, 1972, discloses a method for preparing polyoxyalkylene polyamines.